Sunnybell ST60 3-Tone 16-Channel Wireless Door Bell,Door Chime With Strobe Light Transmits up to 300 feet (open air), Crispy Sound, Weather-proof for outdoor use, CE certified. 16 selectable channels prevent outside interference & allow system expansion Chime only / Flash Only / Chime & Flash selectable 3 tones selectable (Ding, Ding-Dong, Westminster), 90 days money back guarantee and 1 year manufacturer's warranty